I would think if the stitches in your seams are small enough you should not have an issue. I've hand pieced and hand quilted items before but honestly don't remember if I pressed open or to the sides at the time. I'm pretty much an 'open' presser now but also usually machine piece. But I do hand quilt everything. I agree that having less bulk is wonderful. Might have issues with batting bearding? But again, if the stitches in your seams are small, I wouldn't think that would be much of an issue either. Good luck.